1. Field of the Invention
The present invention relates to liquid epoxy resin compositions for use in ball grid array packages. More specifically, it relates to low viscosity liquid epoxy resin compositions which cure rapidly at low temperatures, have good ease of processing, are highly reliable, and can be used as semiconductor device encapsulants to provide ball grid array packages having minimal warpage.
2. Prior Art
Semiconductor encapsulating resin compositions were originally developed and produced in order to protect integrated circuits from outside mechanical and chemical influences, but enhancements in chip reliability have recently brought about a shift in the purposes of encapsulation. For instance, improved heat dissipation and electrical characteristics have taken on greater importance as performance requirements. At the same time, solid progress has been achieved in the development of systems capable of manufacturing and packaging electronic components at low cost. One new type of package that has arisen as a result is the ball grid array (BGA).
In a BGA package, an IC chip is directly mounted onto a circuit board substrate and the chip is covered with a resin composition. The resulting construction in which only one side of the substrate is encapsulated with resin tends to cause the package to warp under the influence of temperature. Resin compositions which contain higher loadings of filler have been proposed in order to reduce the amount of warping, but the increased viscosity of such compositions generally results in poor flow and leveling characteristics.